DE 10 2007 039 828 B3 discloses an electric machine tool having a blower and a battery. The electric machine tool is configured as a hammer drill and has air inlet openings in the rear housing region. The cooling air is drawn in through the housing in the direction of the battery via the motor arranged adjacent to the air inlet openings and exits the housing above the battery.
In order to achieve sufficient cooling of the drive motor, a sufficient amount of cooling air must be conveyed through the housing. With very large air inlet openings the risk that dirt particles can be drawn into the housing is increased. With small air inlet openings, the movement of a large volume flow leads to high flow velocities and negative pressures which likewise can promote the drawing in of dirt particles. In particular, the electronic control is sensitive to heat as well as dirt. Here, a sufficient cooling must be ensured and simultaneously it must be ensured that the electronic control does not become excessively contaminated with dirt.